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EN
Sixty-eight brachiopod species are reported from the upper part of the Skały Formation at Miłoszów (Łysogóry Region of the Holy Cross Mts., central Poland) on the basis of over 2,200 specimens. The fauna is Early to early Middle Givetian in age (timorensis to rhenanus/varcus conodont zones) and thus predates the Middle Givetian Taghanic Bioevent. One new genus and three new species are described. Leiocyrtia Baliński gen. nov. (type species: Leiocyrtia rara Baliński gen. et sp. nov.; Spiriferida, Cyrtiidae) is characterised by a non-costate shell with prominent sulcus and fold and capillate microornament. Undispirifer sidoniae Halamski and Baliński sp. nov. is characterised by transverse shells and dense ribbing. Moravilla andreae Baliński and Halamski sp. nov. is characterised by relatively coarse radial capillate ornament and is the first representative of the genus outside the type species from the Givetian of Moravia. The most abundant species are: Spinulicosta cf. spinulicosta, Antirhynchonella linguiformis, Pentamerelloides davidsoni, Peratos beyrichi, Plectospira ferita, Spinatrypa wotanica (confirmed to belong to that genus and not to Spinatrypina), Ambothyris sp., and Echinocoelia dorsoplana. ‘Spirifer’ quadriplicatus Sandberger and Sandberger, 1856, a rare species known from Miłoszów and the Rhenish Massif, is an orthide and belongs to Teichertina. The relationship between Skenidioides polonicus and S. cretus, formerly understood as anagenesis, is re-interpreted as budding cladogenesis. Davidsonia septata is reported as an epizoan on rugosan corals, a relationship never previously observed in representatives of that genus. Brachiopods represent different palaeoecological groupings, from relatively shallow-water taxa (BA3, globetum) to deep-water mud-dwelling ones (BA5, deeper brachiopodetum). The richest beds are M1-IIa (28 brachiopod species), M3-7 (23 species), and M0-9 (22 species). Eighteen species described here were not known previously in the Holy Cross Mountains, so the corrected total number of brachiopod species from the Middle Devonian of the Łysogóry Region is 140.
EN
The palaeoecology of fossiliferous shales, belonging to the upper part of the Dobruchna Brachiopod Shale Member (= set XIV) of the Skały Formation (northern Holy Cross Mountains), was studied quantitatively in a succession in the transient (1989) trench A, 5.6 m thick, near the village of Skały. The top-Eifelian strata, recording the carbonate crisis during the global Kačák Bioevent, are well known for having a particularly diverse brachiopod fauna. The four brachiopod assemblages, recognised herein, were mainly controlled by the evolving bottom-sediment properties of the outer carbonate ramp basin. Soft, unstable substrates were inhabited by the poorly-diversified Poloniproductus assemblage, associated with a distinctive, ‘incumbent’ set of largely semi-infaunal, generalist species. The pioneer community, as a result of progressive consolidation of bioclast-enriched sediment, evolved toward a more diverse biota. This consequent stabilisation of the substrate resulted in the progressive growth of crinoid thickets or bryozoan-dominated biostromes and patches, associated with rich, subordinate, sessile and vagile benthos. In this stage, diverse brachiopod assemblages were dominated by the pedunculate, eurytopic, ribbed spiriferide Eleutherokomma or specialized orthides (Aulacella, Costisorthis) in the Dobruchna Mbr, and by the expansive, large, free-lying orthotetide Xystostrophia in the overlying set XV of the Skały Fm The cyclic ecological replacement, with the characters of ecological succession in the final phase, was evidently stimulated by an irregular transition from soupy muds to a mosaic of bioclast-rich and firmer, biogenic sediments, within the cyclic pattern of distal tempestite sedimentation. The three episodes of variously reduced deposition rate, recorded in the more diverse benthos, culminated in the pioneer bryozoan/coral reef growth and abundance of epibionts, alternating with times of destructive storm activity and deposition from suspension clouds in the muddy habitats.
EN
The paper includes a taxonomic revision of four externally similar Middle Devonian rhynchonellide species from northwestern Africa (Maïder, Tindouf Syncline) and Central Europe (Eifel, Bergisches Land, Holy Cross Mts.), considered in recent papers as representatives of Kransia Westbroek, 1967 or Nalivkinaria Rzhonsnitskaya, 1968. All four possess a septalium and a multilamellate cardinal process, the assignment to Nalivkinaria, having a bifid cardinal process, is therefore clearly inappropriate. Lebanzuella? issoumourensis (Drot, 1971) is present in the Givetian of Africa; two subspecies, L.? issoumourensis issoumourensis from Jbel Issoumour and L.? issoumourensis smarensis ssp. nov. from Western Sahara, are distinguished by their biometric characteristics. The other two species are included in Kransia (Fatimaerhynchia) subgen. nov. differing from Kransia (K.) in the presence of a septalium; the occurrence of such a variable structure is considered to be justification for distinction at the subgenus level. Kransia (Fatimaerhynchia) goldfussii (Schnur, 1853) is an Eifelian species. Kransia (Fatimaerhynchia?) aff. goldfussii from the Givetian of Bilveringsen is a separate species (larger, more transverse, more strongly ornamented), which is not described because of insufficient material. Kransia (Fatimaerhynchia) signata (Schnur, 1851) is present in the Middle Devonian of Jbel Issoumour, the middle Eifelian of the Eifel and the (upper?) Givetian of the Holy Cross Mountains.
EN
Sixty brachiopod species are reported from the Taboumakhlouf Formation (upper Eifelian) and the Bou Dib Formation (upper Eifelian to Givetian) of Jbel Issoumour, northern Maïder, Anti-Atlas, Morocco, on the basis of collections made by Volker Ebbighausen. The stratigraphy is based on reports of co-occurring trilobite assemblages. The relatively diversified fauna pre-dates the Taghanic event and is dominated in terms of diversity by atrypides and rhynchonellides (11 species each); other frequent species include Poloniproductus varians, Aulacella prisca, Tyersella tetragona, Schizophoria schnuri, Athyris ex gr. concentrica, Yeothyris? sinuata, and Thomasaria simplex. Spinatrypa ennigaldinannae Halamski and Baliński sp. nov. from the upper Eifelian is characterised by a transverse shell, typically 16–18 mm wide with 19–22 ribs. Prodavidsonia ebbigahuseni Halamski and Baliński sp. nov. differs from other representatives of the genus in having nearly flat shells. Eressella coronata Halamski and Baliński, nom. nov. is proposed as a replacement name for the permanently invalid Rhynchonella coronata Kayser, 1871 (non R. coronata Moore, 1861). Thomasaria simplex is documented as being a particularly variable species (costation, tongue, interarea position), so its broad taxonomic treatment is favoured. The brachiopod fauna shows distinct Rhenish affinities (numerous species in common with the Eifel and the Holy Cross Mountains) like the coeval fauna from southern Maïder, described previously. The Middle Devonian brachiopod fauna from the whole Maïder (north, described here and south, described previously) totals 87 species.
EN
The well-known fossiliferous and lithologically variable clay-carbonate series in the Łysogóry Region (northern part of the Holy Cross Mts, central Poland), enclosed between the Middle Devonian Amphipora dolomites and limestones (Kowala Formation) and siliciclastics (Świętomarz Beds), is defined formally as the Shaly-Calcareous Skały Formation. This Upper Eifelian to Middle Givetian, ca. 250–280 m thick unit, consists of marly and clay shales, interbedded many times with various limestone types (including encrinite and biohermal varieties), as well as with marls and siltstones. Its diagnostic feature is the presence of variable skeletal accumulations, formed by exceptionally numerous, well-preserved and diverse macrofauna (including brachiopods, corals, crinoids, bryozoans), described since the 19th century. The stratotype is located in the eastern slope of the Dobruchna stream near the Skały village and belongs to the Silurian to Upper Devonian Grzegorzowice-Skały section. Compared to the previously used term, Skały Beds sensu Pajchlowa (1957), the lower boundary is redefined, owing to a new exposure in the active Skała Quarry, and placed higher, at the base of the famous brachiopod shales (set XIV of Pajchlowa), instead of the formerly accepted lower boundary at the base of set XIII. Set XIV is formally distinguished as the Dobruchna Brachiopod Shale Member. The higher part of the Skały Fm (sets XV–XXVA) is not subdivided further, as the poorly exposed succession, including in particular the type area, precludes a more accurate recognition of lithological variability. The upper boundary of the Skały Fm is placed at the top of set XXV sensu Pajchlowa (1957), corresponding to the boundary between subsets XXVA and XXVB sensu Malec and Turnau (1997). A hypostratotype of the upper boundary is selected in the outcrop M0 at Miłoszów, 2.5 km westwards from the type section, allowing recognition of the diachroneity of lithological change defining the transition from the Skały Fm to Świętomarz Beds. A borehole situated in a key location would be an obvious next step in the further elucidation of the stratigraphic sequence of the Łysogóry Region.
EN
The middle and upper parts of the Skały Fm, Early to Middle Givetian in age, were investigated in four sections at Miłoszów Wood in the Łysogóry Region (northern region of the Holy Cross Mountains, central Poland). The dating is based on conodonts (Polygnathus timorensis Zone to the later part of the Polygnathus varcus/Polygnathus rhenanus Zone; early Polygnathus ansatus Zone cannot be excluded) and spores (Ex1–2 subzones) and, coupled with cartographic analysis and geophysical investigation, allows correlation within the strongly faulted succession. Significant lateral facies variations within the carbonate ramp depositional system in comparison with the better studied Grzegorzowice–Skały section, about 3 km distant, are documented, thanks to conodont-based correlation of both successions. Foraminifers, fungi, sponges, rugose and tabulate corals, medusozoans, microconchids and cornulitids, polychaetes (scolecodonts), molluscs (bivalves, rostroconchs, and gastropods), arthropods (trilobites and ostracods), bryozoans, hederelloids, ascodictyids, brachiopods, echinoderms (mostly crinoids, rare echinoids, holuthurians, and ophiocistoids), conodonts, fish, plants (prasinophytes, chlorophycophytes, and land plant spores), and acritarchs are present. Brachiopods are the most diverse phylum present (68 species), other richly represented groups are bryozoans and echinoderms; in contrast, cephalopods and trilobites are low in diversity and abundance. The muddy, middle to outer ramp biota (200 marine taxa, including 170 species of marine animals, 22 photoautotrophs, 6 forams) represents a mixture of allochthonous shallower-water communities (upper BA3), including storm- and possibly tsunami-affected coral mounds, and autochthonous deep-water soft-bottom brachiopod (e.g., Bifida–Echinocoelia) communities (BA 4–5). The richness and diversity of the Miłoszów biota is relatively high, comparable with other approximately coeval pre-Taghanic ecosystems during the Devonian climatic deterioration (cooling). Preliminary data indicate that in the Holy Cross Mountains, no large-scale replacement of brachiopod (and probably many other benthic ones, like crinoids) communities took place between the Early–Middle Givetian and the Early Frasnian, in contrast to the demise of the Hamilton/Upper Tully fauna in the Appalachian Basin. Such a similarity of pre- and post-Taghanic faunas does not exclude the occurrence of environmental perturbations and transient community turnovers, caused by immigrations during the Taghanic Biocrisis, but evidences the successful recovery of the indigenous biota.
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